The property of viscoelasticity is generally well known in the field, and reference can be made to S. Gravsholt, Journal of Coll. And Interface Sci., 57(3), 575(1976); Hoffmann et al., “Influence of Ionic Surfactants on the Viscoelastic Properties of Zwitterionic Surfactant Solutions,” Langmuir, 8, 2140-2146 (1992); and Hoffmann et al., “The Rheological Behaviour of Different Viscoelastic Surfactant Solutions,” Tenside Surf. Det., 31, 389-400 (1994).
A betaine is any neutral compound carrying separated charges where a positively charged atom, such as a quaternary ammonium or a phosphonium group, is not adjacent to a negatively charged atom, such as carboxylate group. That is, a betaine is a chemical compound that carries a total net charge of zero and is thus electrically neutral, but carries formal charges on different atoms. Notably, it is well known in the field that long chain amido alkyl betaines are effective as viscoelastic surfactants.
Viscoelastic surfactants have continued to grow their role in oil & gas applications and home personal care applications, and the related markets are also expected to continue to show important growth, because of their various advantages over alternative solutions based on polymers. However, such a growth has been inhibited by high cost and low availability of raw materials which are required to produce viscoelastic surfactants.
Among the various fatty acids that can be used as raw materials for the preparation of long chain amido alkyl betaines, erucic acid is often employed in the aforementioned applications because of the high level of viscosity performance at high temperatures attainable by the betaine derived therefrom. For instance, WO 98/56497 (Rhodia Inc.), published on Dec. 17, 1998, discloses viscoelastic surfactants derived from erucic acid. However, erucic acid is a rather expensive raw material with limited availability.
Accordingly, it is required to find alternative viscoelastic surfactants which can be produced in a cost effective manner. That is, there exists a need for an alternative sourcing of raw materials for the synthesis of a long chain amido alkyl betaine and a commercially applicable process for synthesizing the same.